An international team of scientists studying a 75,000-year-old cave in Norway has uncovered unprecedented evidence of a complex community of animals that unexpectedly lived and thrived during the last ice age.
The researchers note their findings, which include bones from several different aquatic and land species, represent the oldest known example of an animal community living together in the European Arctic during the last ice age’s warmer period. They also suggest that a better understanding of animals that existed during the rapid and dramatic climate changes of the period could offer insights that could be “highly relevant for conservation work today.”
“These discoveries provide a rare snapshot of a vanished Arctic world,” said the study’s first author, Dr Sam Walker of Bournemouth University and the University of Oslo. “They also underscore how vulnerable cold-adapted species can be under changing climate conditions, which can help us to understand their resilience and extinction risk in the present.”
Evidence of an Ice Age Community Remained Hidden Until the 1990s
According to the authors of the study detailing their discoveries, significant changes in the European Arctic environment over the last 75,000 years have hindered efforts to paint an accurate picture of life during the last ice age. The study’s senior author, Professor Sanne Boessenkool of the University of Oslo, said that the lack of “well-preserved remains over 10,000 years old” has provided scientists “very little direct evidence of what Arctic life was like” at that time.
To fill in some of those gaps, the researchers turned to the Arne Qvamgrotta cave in the European Arctic. Although this cave served as the home to an ancient community, it was only discovered in the 1990s by employees of a nearby mining company during the construction of a tunnel. Since then, the site has essentially remained unexplored.
In their study, the team conducted a series of excavations in 2021 and 2022 that yielded a treasure trove of ancient relics, hinting at a diverse ancient community of animals that survived and thrived during an exceptionally warm phase of the era’s otherwise arctic conditions. A detailed accounting of the unearthed material revealed remains of 46 different types of animals, including mammal, fish, and bird species.
“The cave has now revealed a diverse mix of animals in a coastal ecosystem representing both the marine and the terrestrial environment,” Boessenkool said.
Follow-up analyses indicated that the animals they’d identified were polar bears, walrus, bowhead whale, Atlantic puffin, common eider, rock ptarmigan, and Atlantic cod.
During this phase, the researchers realized they had also uncovered an extinct species of European collard lemming that had never been found in Scandinavia “until now.” DNA tests determined that the lineages of this species were likely unable to survive when the colder ice age conditions that had briefly paused finally returned.
Struggle to Adapt to Cooling Ancient Climate Could Offer Modern-Day Insights
A comparison of the animal species unearthed in the ancient ice age cave findings previously offered new insights into their adaptation to the local environment and the variety of species that called the cave home. For example, the team believes the presence of ancient migratory reindeer suggests the habitat along the coast was largely ice-free after the glaciers had melted.
The team notes that finding the remains of freshwater fish inside the cave suggests the presence of likely temporary local lakes and rivers. They also note that finding the remains of bowhead whales and walruses, and especially ancient harbour porpoise, which are “known to avoid ice” inside the cave, suggests the sea ice along the coast was likely seasonal.
While the ice age cave discoveries showed an unprecedented example of species variety for their time period and location, the team said their findings also suggest the struggles animals faced when adapting to the changing climate. Specifically, the team stated that it appears entire populations of animals that had adapted to the region during a warmer, wetter period died because they could not migrate to alternative ecosystems when the ice returned and covered the landscape.
“This highlights how cold-adapted species struggle to adapt to major climatic events. This has a direct link to the challenges they are facing in the Arctic today as the climate warms at a rapid pace,” said Dr Walker. “The habitats these animals in the region live in today are much more fractured than 75,000 years ago, so it is even harder for animal populations to move and adapt,” he added.
“It is also important to note that this was a shift to a colder, not a period of warming that we are facing today,” Professor Boessenkool added. “And these are cold-adapted species – so if they struggled to cope with colder periods in the past, it will be even harder for these species to adapt to a warming climate.”
The study “Major discovery of Ice Age bones in a Norwegian cave opens a window into the past” was published in Proceedings of the National Academy of Sciences.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.